Artificial Tears Ease Digital Eye Strain Symptoms but Don't Improve Objective Measures, Study Finds

Preservative-free artificial tears significantly reduce symptoms of digital eye strain in screen users, though the relief doesn't translate to measurable improvements in visual performance or tear film quality, according to new research published in Scientific Reports.

The Spanish study, conducted at the University of Valladolid, examined 30 adults experiencing moderate to severe digital eye strain who used screens for more than four hours daily. Participants were prescribed Systane Ultra UD (Alcon) four times per day for one month.

After treatment, researchers found substantial improvements in symptom scores. The Computer-Vision Symptom Scale (CVSS17) scores dropped from 35.70 to 27.27 points, while Ocular Surface Disease Index (OSDI) scores decreased from 19.99 to 10.52 points, both statistically significant reductions representing a shift from moderate to mild symptom severity.

"Preservative-free artificial tears effectively reduce subjective symptoms in visual display terminal (VDT) users, although this relief does not translate into measurable improvements in visual task performance or tear film metrics," the researchers concluded.

Despite the symptom improvements, the study revealed no significant changes in several objective measures, including blink rate, eye fixations during computer tasks, or tear film stability. Reading speed showed only a slight improvement in normalised values after computer use.

Surprisingly, noninvasive tear film break-up time and tear meniscus height remained unchanged after one month of treatment, though tear volume temporarily increased immediately after drop instillation before returning to baseline levels.

The study's lead author Sara Ortiz-Toquero and colleagues noted that digital eye strain affects approximately 60 million people worldwide, with symptoms particularly prevalent among those spending more than four hours daily on screens. Recent data suggests 65% of American adults and 62.6% of UK and Irish workers using digital devices experience some form of digital eye strain.

The research highlights an important disconnect between how patients feel and what clinicians can measure. While artificial tears provided meaningful symptom relief, allowing participants to function more comfortably, the lack of improvement in objective measures suggests the mechanism may be more complex than simply improving tear film quality.

The study utilised eye-tracking technology to monitor blink rates and fixations during various computer tasks requiring different levels of concentration. Researchers found that tasks demanding greater attention resulted in lower blink rates, consistent with previous research, but artificial tear use did not alter these patterns.

One limitation noted was the single-arm design without a control group, though researchers included two pre-treatment visits to confirm symptom stability and reduce response variability.

The findings may inform clinical practice for optometrists managing digital eye strain. While the study confirms artificial tears can provide symptomatic relief for patients with digital eye strain, practitioners should be aware that this improvement may not correspond with measurable changes in ocular surface parameters.

The research was supported by an investigator-initiated study grant from Alcon.